import 'package:english_words/english_words.dart';
import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
//    final wordPair = new WordPair.random();

    return new MaterialApp(
      title: '第一个flutter app',
      // 更改主题
      theme: new ThemeData(primaryColor: Colors.grey[350]),
      home: new RandomWords(),
//      home: new Scaffold(
//        appBar: new AppBar(
//          title: new Text('welcome'),
//        ),
//        body: new Center(
////          child: new Text('hello world'),
////          child: new Text(wordPair.asPascalCase),
//
////          使用动态的widget
//          child: new RandomWords(),
//        ),
//      ),
    );
  }
}

class RandomWords extends StatefulWidget {
  @override
  createState() => new RandomWordsState();
}

class RandomWordsState extends State<RandomWords> {
  final _suggestions = <WordPair>[];
  final _saved = new Set<WordPair>();
  final _biggerFont = const TextStyle(fontSize: 16.0);

  // 绘制一行
  Widget _buildRow(WordPair pair) {
    final alreadySaved = _saved.contains(pair);

    return new ListTile(
      // 生成单词
      title: new Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),

      // 在末尾添加心型图标
      trailing: new Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),

      onTap: () {
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }

  // listView列表
  Widget _buildSuggestion() {
    return new ListView.builder(
        padding: const EdgeInsets.all(16.0),
        itemBuilder: (context, i) {
          if (i.isOdd) {
            return new Divider();
          }

          final index = i ~/ 2;

          if (index >= _suggestions.length) {
            _suggestions.addAll(generateWordPairs().take(10));
          }

          return _buildRow(_suggestions[index]);
        });
  }

  // 收藏页面
  void _pushSaved() {
    // 路由入栈
    Navigator.of(context).push(new MaterialPageRoute(builder: (content) {
      final tiles = _saved.map((pair) {
        return new ListTile(
          title: new Text(
            pair.asPascalCase,
            style: _biggerFont,
          ),
        );
      });

      final divided =
          ListTile.divideTiles(context: content, tiles: tiles).toList();

      return new Scaffold(
        appBar: new AppBar(
          title: new Text('收藏夹'),
        ),
        body: new ListView(
          children: divided,
        ),
      );
    }));
  }

  @override
  Widget build(BuildContext context) {
//    final wordPair = new WordPair.random();
//    return new Text(wordPair.asPascalCase);
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('listView'),

        // 添加进入收藏页面的图标
        actions: <Widget>[
          new IconButton(icon: new Icon(Icons.list), onPressed: _pushSaved)
        ],
      ),
      body: _buildSuggestion(),
    );
  }
}
